Illuminated display device providing continuous light gradation

ABSTRACT

An illuminated information and advertising device provides continuous light gradation, in white or colored lights. The incandescent lamps are preheated in an electronically controllable manner independently of the information indication. During the course of the indication of information, the brightness of the incandescent lamp can be varied continuously with electronic means in accordance with a given program. The storage and switching elements of the illuminated board can also be controlled by means of bipolar signals and are also provided with separately controllable inputs for varying the light gradation and/or for the preheating. This controllability ensures the compatability of the electronic control circuit of the illuminated board with the electronic control circuit of the color contrast devices, which are equipped with magnetic indicating elements; thus, it is possible to operate, in conjunction with an outdoor lighted board, easily readable color contrast devices disposed indoors, by means of which complete control can be exercised.

United States Patent [191 Mandzsu et al.

1 1 July 30, 1974 ILLUMINATED DISPLAY DEVICE PROVIDING CONTINUOUS LIGHT GRADATION [75] Inventors: Jozsef Mandzsu; Laszlo Jagicza;

Attila Peter; Laszlo Kellner; Sandor Jodal, all of Budapest, Hungary [73] Assignee: F ok-Gyem Finommechanikai es Elektronikus Muszergyarts 82., Budapest, Hungary 22 Filed: Feb. 5, 1973 21 Appl. No.: 329,316

[30] Foreign Application Priority Data Primary Examiner.lohn W. Caldwell Assistant ExaminerMarshall M. Curtis Attorney, Agent, or FirmYoung & Thompson 5 7 ABSTRACT An illuminated information and advertising device provides continuous light gradation, in white or colored lights. The incandescent lamps are preheated in an electronically controllable manner independently of the information indication. During the course of the indication of information, the brightness of the incandescent lamp can be varied continuously with electronic means in accordance with a given program. The storage and switching elements of the illuminated board can also be controlled by means of bipolar signals and are also provided with separately controllable inputs for varying the light gradation and/or for the preheating. This controllability ensures the compatability of the electronic control circuit of the illuminated board with the electronic control circuit of the color contrast devices, which are equipped with magnetic indicating elements; thus, it is possible to operate, in conjunction with an outdoor lighted board, easily readable color contrast devices disposed indoors, by means of which complete control can be exercised.

7 Claims, 2 Drawing Figures PATENTED JUL 3 0 I974 sum 2 or z ILLUMINATED DISPLAY DEVICE PROVIDING CONTINUOUS LIGHT GRADATION The present invention relates to illuminated display devices providing a continuous light gradation, for the display of selectively programmable visual data or other displays, by means of specific light effects. The invention is useful in a number of fields, e.g., the display of information during sporting events.

Display devices with incandescent lamps have become very popular in the field of illuminated displays and advertising. A great variety of structural or circuit arrangements have been constructed, wherein high reliability and simple construction have been ensured by modern semiconductor technology.

Such devices fall in two groups, according to whether they employ fixed letters and images, or movable letters and images. They can also employ white light or colored light. In all such systems, however, means are provided for storing the information determining the switched-on or switched-off condition of the incandescent lamps.

By first feeding the information to be displayed into an electronic storage means of large capacity and then causing the information to be displayed, by rapid readout from the storage means, on the display board, or on several boards, and by illuminating according to the component parts of this information,.by means of corresponding programming, the board for a short period of time, for example as in case of commercial advertising, then in this way a continuously variable visual display is produced.

The chronological frequency of such changes or such programming is generally limited only by the inertia or response time of the incandescent lamps.

Although the known devices have a high speed of display as an advantageous feature, these devices also exhibit several disadvantages which impair their serviceability. Among these known devices are, for example, those varying the light intensity of the incandescent lamps in dependence on the external illumination, generally produced by a connection to the taps of the winding on the primary side of the transformer and caused by the output. The known devices make it possible, on the one hand, to regulate the light intensity of the switched-on incandescent lamps only in a very general way, which is often insufficient under variable illumination conditions, particularly when considering polychromatic displays; on the other hand, highvoltage insulating problems occur with respect to the units connected to the no-load primary windings.

Another disadvantage of known devices is that, for

.. example in sports data display devices, it is impossible to connect to the control unit of the illuminated board a control panel which operates with light contrast and can be desirably small and compact. Also, there is the disadvantage that even a brief failure of the supply voltage of the incandescent lamps in the display board results, in the electronic systems, in loss of the stored information and/or of the displayed image and/or letter.

sion of an illuminated display device with continuous light gradation, which makes possible the simultaneous and/or sequential employment of a variety of display techniques.

Finally, it is an object of the present invention to provide an illuminated display device with continuous light gradation, which will be relatively simple and inexpensive to manufacture, easy to install, operate, maintain and repair, and rugged and durable in use.

Briefly, the objects of the present invention are achieved, by providing an illuminated display device providing continuous light gradation and comprising incandescent lamp indicator elements, a data input unit, power supply means. The device is characterized in that there are associated with the electronic storage switch pertaining to each incandescent lamp at least one input controlling the light gradation of the incandescent lamp and not requiring any synchronization with respect to the power supply, and also at least one information input controllable by bipolar signals for input as well as erasure.

The input of the electronic storage circuit elements also includes a large-hysteresis Schmitt trigger, made up of inverters, preferably two in number, wherein one inversion level is adjusted to lie in the positive logical range and the other in the negative voltage level range.

The device can also be constructed so that the individual inputs controlling the light gradation of the incandescent lamp or lamps are combined in groups.

According to another feature of this invention, among the inputs controlling the light gradation, the preheating of the incandescent lamps is ensured, and one or more of these inputs ensure the uninterrupted light intensity control of the incandescent lamps.

Also, the inputs controlling the light gradation of the incandescent lamps are controlled in groups by means of signals or pulse sequences which are chronologically shifted with respect to one another.

Furthermore, the inputs serving for varying the light gradation of the incandescent lamps are controlled in the circuit operation by means of a variable pulse width.

According to a variant, the inputs controlling the light gradation of the incandescent lamps are connected to a closed control circuit.

According to a further variant, the device can also be constructed so that the information input controllable by bipolar signals is connected electrically separately and in an inductive manner to the electronic control unit for the passive magnetic indicating elements.

A great advantage of this invention resides in that it provides a continuous variation of the light gradation of the incandescent lamps or groups of lamps. This variation can be effected by manual control or automatically in dependence on the external illumination of the lighted board in such a manner that a photoelectric sensor mounted at the lighted board perceives the external illumination and, with the aid of a control circuit, adjusts the light gradation of the incandescent lamps in each case in correspondence with the outdoor illumination level.

The measurement of the outdoor light level can also be effected, for example, in a line-by-line manner, and in this case, when a shadow falls on a line, the optimum light gradation of this shadowed light is correspondingly adjusted.

Furthermore, in the particular field of sports data display, there is the advantage that the device can be used, for example, in athletic competition where several events take place simultaneously on the field, in which case this invention provides that the light gradation of the lines reporting certain results is adjusted to the maximum, and the light gradation of the remaining lines is adjusted to close to the limit of readability, thus emphasizing the results of the latest events, for example, in contrast to earlier events.

By setting the light gradation to barely the amount needed for preheating, there is the possibility of displaying on the board a latent image, whereupon the light gradation of superposed displayed information can be varied at will, which makes it appear, in cases of advertising displays, as if the displayed information is, so to speak, dynamically movable, by varying the light gradation in accordance with a predetermined program. This provides a novel method for gaining attention, in contrast to known neon light advertising devices, since reprogramming is possible at any time. By means of a like method, it is possible, for example, in the case of illuminated boards having a homogeneous screen, to transpose the information into a negative image, which likewise provides an effective advertising design, without having to reprogram the information.

A further advantage of this invention resides in that an outdoor illuminated board is electrically separated from the electronic control circuit; the board can be disconnected from the circuit at any time, and the control cables can be detached without causing any changes on the outdoor board, since the information is preserved.

It is likewise possible to disconnect the power or supply unit which feeds power to the incandescent lamps, without causing a change of the content of the electronic information on the board.

Finally, as a further important advantage, the device is completely compatible, with respect to its control, with the systems made up of magnetic indicating elements, and thus it can be operated in parallel with information indicating devices that employ passive magnetic indicator elements. This affords the possibility to operate, in addition to an outdoor illuminated board of high energy requirements, a small panel in parallel therewith, indoors, which panel, however, has the same number of scanning or image points as the outdoor board and works with magnetic indicator elements, for example a visual information panel. With the aid of this panel, the control of the information can be ideally effected.

Other objects, features and advantages of the present invention will become apparent from a consideration of the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of the device; and

FIG. 2 shows the logic structure of the storage and switching unit pertaining to an incandescent lamp.

Referring now to the drawings in greater detail, and first to FIG. 1, an information input unit 31 is shown, which actuates the electronic control unit 32 by means of series or parallel signals. The electronic control unit 32 produces the position-selecting signals in accordance with the two coordinates, as well as the bipolar information signals. The signals pass, via cables, to the control panel 33 comprising the magnetic indicator elements, as well as to the illuminated board 34 containing the incandescent lamps.

The output X of the electronic control unit 32 ensures the automatic variation of the light gradation of the activated or switched-on incandescent lamps on the luminous board 34, via the closed control loop, whereas the output Y makes it possible to control the above-mentioned incandescent lamps by a pre-fed program or in a manual manner. The switch-over is effected by switch K,.

The incandescent lamps of the luminous board 34 are supplied with power by the high-power three-phase supply source 35.

The control cables connected to the illuminated board and to the control panel (which cables number 35 n m, wherein n is the number of lines, m is the number of columns, and 35 is the number of information channels) can be disconnected by means of the switches K, and K whereby the illuminated board and the control panel, completely separated from the remaining units, still ensure the electronic storage of the written-in information.

FIG. 2 shows the logic structure of the storage and switching unit pertaining to an incandescent lamp. In FIG. 2, the bipolar output of the electronic control units is connected to the control point A. The control points A of the individual letter fields associated with the same position are combined with or multiplied by each other.

The signals arriving at the inputs M, N, of the letter position selecting unit determine in which letter field the control signal present at the points A is to become effective. The number of inputs M, coincides with the number of lines of the illuminated board letter field. The number of inputs N, coincides with the number of columns of the letter field. In this manner, any desired letter fields can be selected as a matrix in the coordinate system with the signals arriving at points M, N,. The switch 6, effecting the selection of the position in the letter field, can be switched on by excitation of its winding 16. The diode l5 ensures the selective or matrix-like controllability of the exciter winding 16.

The poles of the letter field selection switch 6 are electrically connected to the cathode and/or anode terminals or units of the diodes 2, 2 3, 3 which are connected to the one terminal or unit of the exciter coils 1, 1 receiving the information and which ensure a selective bipolar controllability.

The cathode of the diode 4 is connected to the point joining the cathodes of the diodes 2, 2 the anode of this diode is connected to ground. The anode of the diode 5 is connected to the point joining the anodes of the diodes 3, 3 while the cathode of this diode is connected to ground.

The above-mentioned diodes effect current compensation during the course of the control procedure, since one portion of the information-receiving exciter coils l, 1 is controlled with a positive potential, and the other portion is controlled with a negative voltage, in accordance with the code of the respectively displayed characters. If the number of positive and negative excitation directions coincides, no current flows through the diodes 4 and 5. However, once the equilibrium is upset in one of the two directions, the diodes 4 and 5 permit the flow of compensating currents. The coil 17 is inductively coupled with the information-receiving excitation coil 1,; and coil 17 is connected at one end to ground and at the other end B, via the series resistor 7, to the input of the inverter 9. The output of the inverter 9 is electrically connected to the input of the inverter 10. The output of the inverter 10 is likewise electrically connected to the input of the inverter 9 via the coupling member 8.

The inverters, connected in feedback manner as set forth above, have the effect, similarly to a Schmitt trigger with a large hysteresis, that in case a positive trigger signal is present at point B, a logic YES or AND level remains at E as stored information and, in case a negative trigger signal arrives at point B, a logic ZERO or NOR level appears at E. The output E of the inverter 10 is also connected to one of the inputs of inverter 11, whereas the other input of the inverter 11 is electrically connected with C, the source of control signals.

The control signals coming from C effect the control of the continuous light gradation by changing the degree of modulation. The time changes in the basic period T. The output F of the connected inverter 11 is joined to one of the inputs of the inverter 12, while the other input is electrically connected to point D.

The signals coming from point D control the extent of preheating, thus also varying the degree of modulation. The signals arriving at point D are likewise based on a basic period T coinciding with the basic period at point C, and the time t, varies in length in correspondence with the preheating.

T is not in synchronism with the mains frequency. The output G of the inverter 12 is connected to the base of the switching transistor 14 via the coupling member 13. The emitter of the switching transistor 14 is connected to ground potential and the collector H is connected to one terminal of the incandescent lamp L. The other terminal of the incandescent lamp L is connected to the supply voltage +U, whichis a voltage rectified without filtering.

The inputs from C controlling the light gradation are combined in groups, for example in dependence on the lines of letter fields; the inputs from D controlling the preheating are combined for the entire board.

In case polychromatic images are provided, for example by means of several colored incandescent lamps, the units connected to point E for each incandescent lamp must be multiplied in correspondence with the number of incandescent lamps. Thus, for example, the continuous light gradation in case of four colors can be controlled with the aid of four control points C,- C, in accordance with the individual colors, wherein the four control points D, D, are combined as common preheating control points. If the control points C, C, are controlled together in combination, the light gradation of each color hue will vary in the same manner.

There is also the possibility of controlling the control inputs C, C, independently of one another and thereby achieving very effective light and/or color combinations. Thus, the information can, for example, be changed continuously from one color to another color or shade of color.

The operation of the invention is as follows:

The signals from the information input unit 31 arriving in series code, for example from a teletypewriter, are received by the electronic control unit 32. As an example, the teletypewriter codes are used to select first the line M, and then the column N, of the letter fields of the illuminated board. In this way, the switch 6 is energized. After determining the write-out position, it is possible to obtain, by depressing, for example, the letter A, the coded signals corresponding to this letter at the output points of the electronic control unit 32.

The pulses, positive or negative according to the code, excite, via the information channel lines (for example 35 in number), on the one hand the exciter windings of the magnetic indicator elements of the control panel and, on the other hand, the exciter coils 1, -1 of the luminous board receiving the information. In accordance with the directions of excitation, positive or negative trigger or differentiated signals appear at the points B of the storage switches pertaining to the individual incandescent lamps. When a positive trigger signal appears at point B, then a logic YES or AND level appears also at the output E and indicates that the incandescent lamp must indicate a datum, i.e., it must light up. In accordance with the series of pulses coming from point P, the inverter 11 is connected. If a logic YES level is present at its input, then a logic ZERO or NOR level appears at its output.

Thus, independently from point D, a logic YES or AND level appears at the output G of the inverter 12 and renders the switching transistor 14 conductive; as a result, the incandescent lamp L lights up.

Since, within the period T, the time t is continuously varied, there is also a continuous change in the degree of modulation or light gradation of the incandescent lamp L.

When a negative trigger pulse appears at the input B, then a logic ZERO or NOR level also appears at the input E. Then, a logic YES or AND level occurs at the output F, independently of input C. Since the pulse 1, coming from point D is very small as compared to T, the logic YES or AND level appears at the output G for only a very short period of time; consequently, the incandescent lamp L will be lighted only very briefly and in a hardly perceptible manner. In this way, the incandescent lamps are preheated even without any display of information. When interchanging the points C and D by switching, the negative image of the displayed information is produced on the lighted board.

The above procedure takes place in connection with each individual incandescent lamp of the letter field.

From a consideration of the foregoing disclosure, therefore, it will be evident that all of the initially recited objects of the present invention have been achieved.

Although the present invention has been described and illustrated in connection with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from the spirit of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.

Having described our invention, we claim:

1. In an illuminated display device comprising a plurality of incandescent lamps arranged so as to comprise indicia, an information input unit, and power supply means for said lamps; the improvement comprising means for providing continuous light gradation of said lamps and comprising, in association with each said incandescent lamp, at least one input controlling the light gradation of the incandescent lamp and free from synchronization with respect to said power supply means,

at least one information input for said lamp, and means to provide bipolar signals to said information input.

2. A device as claimed in claim 1, said input for said lamp comprising a Schmitt trigger with large hysteresis, said trigger comprising inverters such that one invention level corresponds to a positive signal polarity and another inversion level corresponds to a negative signal polarity.

3. A device as claimed in claim 1, in which plural inputs control the light gradation of the incandescent lamp, said inputs being combined in groups.

4. A device as claimed in claim 3, and means controltrol circuit in which said input for said lamp is disposed. a a 

1. In an illuminated display device comprising a plurality of incandescent lamps arranged so as to comprise indicia, an information input unit, and power supply means for said lamps; the improvement comprising means for providing continuous light gradation of said lamps and comprising, in association with each said incandescent lamp, at least one input controlling the light gradation of the incandescent lamp and free from synchronization with respect to said power supply means, at least one information input for said lamp, and means to provide bipolar signals to said information input.
 2. A device as claimed in claim 1, said input for said lamp comprising a Schmitt trigger with large hysteresis, said trigger comprising inverters such that one invention level corresponds to a positive signal polarity and another inversion level corresponds to a negative signal polarity.
 3. A device as claimed in claim 1, in which plural inputs control the light gradation of the incandescent lamp, said inputs being combined in groups.
 4. A device as claimed in claim 3, and means controlling said groups by means of signals chronologically shifted with respect to one another.
 5. A device as claimed in claim 1, there being a plurality of said inputs for said lamp one of which ensures preheating of the lamp and at least another of which controls the continuous light intensity of the lamp.
 6. A device as claimed in claim 1, and means controlling said input for said lamp by means of a variable pulse width.
 7. A device as claimed in claim 1, and a closed control circuit in which said input for said lamp is disposed. 